Open Gmail in a web browser
Sign in to your Google account
Open the email you want to download
Click the three-dot menu in the email
Select Download message
Save the .eml file to your device
To download multiple emails, use Google Takeout
Go to takeout.google.com
Sign in to your Google account
Deselect all products
Select Mail
Choose the data format and export options
Click Next step
Choose delivery method, file type, and file size
Click Create export
Download the exported file when it is ready
To save an email as a PDF, open the email
Click the three-dot menu
Select Print
Choose Save to PDF as the destination
Click Save
Select a folder and save the file